If you are just looking to kill existing grass in a small area, you should treat with a professional glyphosate product like our Ranger Pro product. This kills grass for longer than typical round up, but eventually it will grow back. If you really do not want anything to grow back, you can use a soil sterilant. These products need to be used according to the label though, they are very powerful and can move through the soil, so if there is anything around the posts you would want to not kill, you should not use a soil sterilant.
Answer last updated on: 10/02/2011